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The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club T Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The P Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL C The Pi. XL Club The Pi. XL Club The Pi. XL Club T Pi. XL Club The Pi. XL Club The Pi. XL Club The P Club The Pi. XL Club The Pi. XL Club The Pi. XL C The Pi. XL Club The Pi. XL Club T Pi. XL Club The Pi. XL Club The P Club The Pi. XL Club The Pi. XL C The Pi. XL Club The Pi. XL Club T Pi. XL Club The Pi. XLThis resource is strictly for the use of member schools for as long as they remain members of The Pi. XL Club The Pi. XL Club. It may not be copied, sold nor transferred to a third party or used by the school after membership ceases. The Pi. XL Club The Pi. XL Club The Until such time it may be freely used within the member school. Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The All opinions and contributions are those of the authors. The contents of this resource are not connected with Pi. XL Club The Pi. XLnor endorsed by any other company, organisation or institution. Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Club The Pi. XL Clubwww. pixl. org. uk The Pi. XL Club The Pi. XL Club Thenumber Pi. XL Club 07321607 The Pi. XL Club The P Pi. XLClub. The Ltd, Pi. XL Company Club The Pi. XL Club The Pi. XL C The Pi. XL Club The Pi. XL Club T Practical Guide Chemistry Rates of Reaction This document contains: • • • Links to You. Tube clips showing the practical procedure Information from examination boards AQA, OCR, Edexcel Potential examination questions and answers Commissioned by The Pi. XL Club Ltd. November 2016 © Copyright The Pi. XL Club Ltd, 2016
Required practical – exam boards • AQA
Practical procedure: Rates of Reaction Video 1 Video 2 Images from: http: //www. rsc. org/learn-chemistry/resource/res 00001916/the-rate-of-reaction-of-magnesium-with-hydrochloricacid? cmpid=CMP 00006119 http: //www. rsc. org/learn-chemistry/wiki/index. php%3 Ftitle%3 DExpt: The_effect_of_concentration_on_reaction_rate%26 oldid%3 D 4560
Possible examination style questions 1. The rate of a reaction between hydrochloric acid and calcium carbonate can be increased by increasing the concentration of the acid. Explain why, using ideas about collisions between particles. 2. Plot the following from a reaction between HCl and Mg. Time/ seconds 10 20 30 40 50 60 70 80 90 Total volume of gas/ cm 3 7 15 20 23 24 25 25 3. Describe the pattern in the graph. 4. Use the graph to calculate the rate of reaction over the first 20 seconds. 5. The experiment was repeated using magnesium powder. Draw a line of best fit for this new reaction.
Possible examination style questions answers 1. The rate of a reaction between hydrochloric acid and calcium carbonate can be increased by increasing the concentration of the acid. Explain why, using ideas about collisions between particles. ANSWER: • More reacting particles • In the same space • More frequent collisions between reacting particles
Possible examination style questions answers 2. Plot the following from a reaction between HCl and Mg Time/ seconds 10 20 30 40 50 60 70 80 90 Total volume of gas/ cm 3 7 15 20 23 24 25 25 ANSWER: • Sensible scale • Correct plotting • Labels on axes • Line of best fit through points
Possible examination style questions answers 3. Describe the pattern in the graph. ANSWER: • Reaction steady for first 20 seconds • Between 20 -50 seconds the reaction slows • Reaction completed after 55 -60 seconds • One of the reactants has been used up
Possible examination style questions answers 4. Use the graph to calculate the rate of reaction over the first 20 seconds. •
Possible examination style questions answers 5. The experiment was repeated using magnesium powder. Draw a line of best fit for this new reaction. ANSWER: • Line should start steeper than initial line • Levels off earlier than initial line • Finishes at 25 cm 3
Key questions: • What is the balanced equation for the reaction? • What are the state symbols for the reactants and products? • What is the best practical method to determine the rate of this reaction and why? • What are two different methods of collecting and measuring the volume of gas produced? • What is the biggest error in this experiment? • How could you reduce this error? • How do you decrease the size of the marble chips? • What specific safety precaution should you take when decreasing the size of the marble chips? http: //qualifications. pearson. com/content/dam/pdf/GCSE/Science/2016/teaching-and-learning-materials/GCSE-9 -1 -Sciences-core-practical-guide. pdf
Key questions: • How does this affect the surface area of the marble chips? • What effect does this have on the rate of reaction? • How can you explain this effect from graphs of volume of gas plotted against time for two different sizes of marble chips? • How can you calculate the rate of reaction from these graphs? • What needs to be kept the same when you repeat the first experiment but use a different size of marble chips? • How could you decrease the concentration of the hydrochloric acid? • What effect will decreasing the concentration of hydrochloric acid have on the rate of reaction? http: //qualifications. pearson. com/content/dam/pdf/GCSE/Science/2016/teaching-and-learning-materials/GCSE-9 -1 -Sciences-core-practical-guide. pdf
Key questions: • How do you explain this effect in terms of particles and collisions? • What is seen when sodium thiosulfate solution reacts with dilute hydrochloric acid? • What safety precautions should you take in this investigation? • What is the best practical method to determine the rate of this reaction and why? • How do you change the temperature of the solutions? • What happens to the time taken for the reaction to occur as the temperature increases? • How do you explain this change in terms of the energy of the particles and collisions? http: //qualifications. pearson. com/content/dam/pdf/GCSE/Science/2016/teaching-and-learning-materials/GCSE-9 -1 -Sciences-core-practical-guide. pdf
Summary document A summary document is also available on Huddle which contains all the relevant information about this practical from the different examination boards. It includes practical methods and other potential examination questions.
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